1. Field of the Invention
The present invention relates to a steering wheel shaft bearing for vehicles for rotatably supporting the steering shaft to a steering column.
2. Description of the Prior Art
Heretofore was inherent in the bearing of this type a problem that due to some machining errors taking place on the inner peripheral surface of a steering column to which the bearing is fitted and the dimension in diameter of the steering shaft, the bearing gap sometimes becomes excessively greater so as to cause noise due to vibration of the vehicle or the bearing gap becomes excessively small thereby to increase the steering torque and thus resulting in difficulty of keeping equilibrium between the occurrence of back-lash noise and the increase in torque.
To solve the problem inherent in the prior art technology was proposed an invention such as disclosed by Japanese Patent Application No. 88104-1979, wherein use is made, in retaining a plurality of needle-like rollers for the steering wheel shaft of a vehicle, of a cylindrical race member circumscribing the needle-like rollers and having a straight split formed and extending obliquely through and along the whole axial length thereof so as to improve operability and sealing performance of the bearing.
However, the above-proposed invention has been found to have the following disadvantages due to the specific construction of the cylindrical race member.
The cylindrical race member of the prior art technology has a generally C-shaped cross section with an obliquely extending straight slit so that if a number of the cylindrical race members are stored in a container or the like, they have normally open slits which are liable to catch one another through the opening slits just as in the case of puzzle rings so that before the use, they must be separated beforehand from one another, thus unavoidably requiring extra labour and excessive working steps in the manufacture of the bearing units.
Further, an obliquely extending straight slit was provided in the prior art cylindrical race member, therefore when, in practical use, the opposing edges of the slit are brought into contact either on the whole length of each of the opposing edges or only at the intermediate portions thereof, the opposing edges are forced to displace from each other in the axial direction of the cylindrical race member, such a sidewise displacement in turn resulting in poor dimensional accuracy of the race member.
Furthermore, when one of the opposing edges runs on the other when the race member has been assembled with the steering wheel column, the thus superimposed portion forms an undesirable level difference, resulting in rapidly enhanced torque of the bearing.